Apparatus used in the development of optical-diffraction methods for the solution of problems in X-ray analysis

Helical conformation of cis‐1,4 poly (2‐t‐butyl‐butadiene)

“…A model of such a helix is easily obtained admitting a cis conforma- tion about the double bond: no helical conformation is reasonably possible with a trans form, in addition to the fact that in such a conformation too short a distance between the methyl groups of the (CH3)3 Cand the CH2 groups of the chain would be present. Preliminary calculations of the diffracted intensity, carried out by means of an optical diffractometer (5,6) give further evidence of the proposed helix, the projection of which is shown in Figure 2. The prominent feature of this model is that the plane containipg the double bond is practically perpendicular to the chain axis.…”

The diffraction of X-rays by a cylindrical lattice. III

“…The diffraction apparatus used was the actual apparatus described by Hughes & Taylor (1953). The pinhole source used was 10 microns in diameter in order to obtain the highest possible resolution.…”

Instrumental aspects of image analysis in the electron microscope

“…A plane mirror E 'folds' the beam so as to make observation more convenient. A full description of the construction has been given by Hughes & Taylor (1953). Bragg & Lipson (1943).…”